At present, applications of a touch panel system to various electronic devices, e.g., a mobile information device such as a smartphone and a vending machine such as a ticket bending machine, have rapidly been increased. A touch panel mainly used in such a touch panel system has been a resistive film type touch panel. However, in recent years, a projected capacitive type touch panel is becoming popular because of its capability of accepting multi-touch.
As an example of such a touch panel system, Patent Literature 1 discloses a command input device. The command input device includes a touch panel, a touch time detecting section, a touch frequency detecting section, a touch interval detecting section, and an input command determining section. The touch time detecting section detects time during which a finger is continuously making contact with the touch panel. The touch frequency detecting section detects the number of times that the finger touches the touch panel. The touch interval detecting section detects an interval from when the finger is off from the touch panel and to when the finger makes contact with the touch panel. The input command determining section determines an input command on the basis of detection results of the touch time detecting section, the touch frequency detecting section, and the touch interval detecting section.
FIG. 7 is a flowchart for describing an operation of the command input device disclosed in Patent Literature 1. As illustrated in FIG. 7, the command input device is arranged such that: (i) a command can be inputted on the basis of time, a frequency, and an interval of touch by the finger to the touch panel (S501 to 507); (ii) a command is determined on the basis of the inputted command (S508); (iii) an operation is selected on the basis of the determined command (S509); and (iv) the touch panel is controlled in accordance with the selected operation (S510).